Multi-tier, stackable planters are generally known in the art. While planters comprised of stackable units have been shown capable of holding multiple plants at a periphery of the planter units, none of the prior art planters provide a system that is useful for decorating or concealing a large post, tree, or the like, nor have prior art planters provided a system that includes a central recess feature for adding a larger plant to the center of the planter, when assembled in a stacked condition. The present invention is directed to a modular, stackable planter system that addresses these needs and other deficiencies in prior art planters.